Originating in 1960, Lisp is second only to Fortran as the oldest
programming language still in use today. Historically used for research,
artificial intelligence, and mathematics, Lisp remains relevant in these
fields, as well as in quantum computing research and other cutting-edge
In the mid-1970s, researchers sought high-performance, single-user,
interactive machines due to the constraints of running their code on large
multi-user mainframes. Such machines would allow for more efficient and
flexible research and development. Richard Greenblatt at the MIT AI Lab
spearheaded the development of the first dedicated Lisp machines, including
the successful CONS machine and later CADR machines.
MACSYMA, a symbolic mathematics program written in Lisp which consumed
significant resources on the PDP-10 running ITS, was a key motivator for
the Lisp Machine's creation.
LispM hackers in residence, including Daniel Weinreb (DLW), David Moon
(MOON), Richard Stallman (RMS), John L. Kulp (JLK), Mike McMahon (MMcM),
and others, were responsible for the overall system development. Kulp
designed the legendary Space Cadet keyboard, known for its unique key
arrangements and symbols, and Moon and Weinreb wrote the first and second
Lisp Machine editors (EINE, ZWEI) respectively.
Brad Parker developed the first working CADR simulator (usim), which
emulates the MIT CADR, and with the Lisp Machine microcode running on top,
allows users to explore the historic system and its unique features.
Until recently, only up until system 78 of the LISP operating system and
microcode from MIT could be emulated. Alfred M. Szmidt (AMS) received
copies of backup tapes containing systems 98 and 99, dating from 1983 and
1984, respectively, and was able to get them running after a decade of
effort. The bootstrap process was an impressive hack, due to the Lisp
Machine's use of network booting and a mixture of compiled and uncompiled
code. Szmidt has now iterated the distribution to system 100 with all of
his fixes included.
This marks the first time in 35 years that anyone can use this environment,
designed to support AI and computational research at the cutting edge. The
windowing and graphical feel of the environment stand out, and the Lisp
machine and CADR processor allow users to dive deep into the operating
system's inner workings. The line between compiled and source code is thin,
and users can open and read almost everything.
The CADR machine served as the foundation for commercial products sold by
LISP Machines, Inc., founded by Richard Greenblatt, and Symbolics, founded
by MIT AI Lab ex-administrator Russell Noftsker. The emulator provides a
glimpse into the height of 80s MIT hacker culture by booting to MIT System
Find more information and try the system out yourself via AMS's
Or visit https://tumbleweed.nu/lm-3